1. Field of the Invention
The present invention relates to short-wavelength electromagnetic-radiation generators that generate electromagnetic radiation having short wavelengths by causing photons and electrons to collide.
2. Description of the Related Art
In lithography applied to the production of semiconductor devices, a base is formed and patterned by performing predetermined exposure of a resist, developing the exposed resist, and etching the developed resist.
Recently, with refinement of design rules, it is necessary to use photolithography using a short-wavelength electromagnetic-radiation source. A KrF excimer laser (whose wavelength is 248 nm), an ArF excimer laser (whose wavelength is 193 nm), etc., are used as the short-wavelength electromagnetic-radiation source.
For obtaining short-wavelength electromagnetic radiation, electron-beam lithography, and X-ray-beam lithography to which synchrotron radiation is applied, are under consideration.
The electron-beam lithography is suitable for limited production of a wide variety of goods, but is not suitable for mass production due to its low throughput. The X-ray-beam lithography to which synchrotron radiation is applied requires a large, complicated apparatus as an X-ray source, which disadvantageously increases cost in production of semiconductor devices.
Accordingly, a method is being researched utilizing the inverse Compton effect as a technique which will allow a small apparatus to be used to yield short-wavelength exposure electromagnetic radiation. An electromagnetic radiation source which utilizes the inverse Compton effect uses electromagnetic-radiation scattering caused by electrons moving at a relativistic velocity, to supply photons with the energy of the electrons, whereby shortening the wavelength of the scattered electromagnetic radiation.
In the inverse Compton effect, a problem occurs in that the yield of obtained photons in X-ray regions is small because a scattering cross section based on the electrons and the photons is an extremely small value of 10.sup.-27 cm.sup.2. Therefore, in lithography, sufficient X-ray energy cannot be produced, which is a likely problem in practice.